Documents, including email messages, generated by employees in an organization often contain sensitive information that should be made available only to a selected set of recipients who are authorized to view such information.
Consider, for example, an email message generated by an employee in a company. The email message typically includes the employee number and a name of a department where the employee works. Recipients of the email message may include other employees in the company, as well as certain customers of the company. Both categories of the recipients may have different requirements regarding sensitive information contained in the email message.
Classifying email messages and ensuring that only authorized persons are given access to the sensitive information contained in the email messages is important to the appropriate functioning of the organization. Message classification has a number of advantages that include the following:                It provides user accountability;        It reduces the disclosure of sensitive information to unauthorized persons;        It facilitates the enforcement of rules regulating the email message distribution for the organization; and        It enables the use of security technology to redact sensitive parts of an email message sent to a recipient that does not have the right to view such information.        
The classification of segments of email messages, to be also referred to as portions in this patent application, has been a requirement in military and government environments for many years. The classification requirements have been set out by certain organizations, such as the US Department of Defense Controlled Access Program Office (CAPCO). Up to this point in time, such classification has been performed manually by inserting appropriate classification marks to a chosen segment of an email message. The whole process of inserting marks is labor intensive, tedious, and prone to errors, since users have to type each mark in a proper format.
Therefore there is a need in the industry for developing an improved process for classifying and redacting segments of electronic document, including email messages.